The invention relates to a land, sea or air vehicle provided with a cabin having windows or windscreens, under at least one of which a dashboard or panel provided with ventilation slots is disposed.
In all motor vehicles a device is provided for heating the ventilation air which is to be directed onto the windscreen or to the passengers, making use of a heating radiator in which the ventilation air can be brought into a heat exchange relationship with the engine cooling water. Heated air is necessary in order to demist or defrost the windscreen. One problem is that when starting off with a cold engine the cooling water is still cold, so that the ventilation air cannot be heated, and therefore demisting or defrosting is impossible. This can lead to dangerous situations. In modern motor vehicles increasing use is made of glass, so that this problem becomes more urgent. Furthermore, engines are becoming more and more efficient, so that it takes longer for engine heat to become available for heating the interior of the vehicle.